Scientists Rebuild Iceman Genome
From Hair Sample

Gregory Mone

Special to AOL News

(Feb.
11) – An international team of scientists has rebuilt the genome
of an ancient human for the first time. The man, dubbed Inuk, was a
Palaeo-Eskimo who lived about 4,000 years ago on the western coast of
Greenland.

Analysis of his genome, reported in the current issue of Nature,
has given researchers new insights into the extinct Saqqaq culture –
the first known to inhabit Greenland – but the work also revealed a
variety of Inuk's physical traits. He had brown eyes, brown skin,
shovel-shaped front teeth and a problem with dry earwax. He might have
been going bald, too, but not completely. In fact, Inuk managed to
leave behind a very valuable clump of hair.

The lead scientists on the 53-person team, geneticists Eske Willerslev
and Morten Rasmussen at the University of Copenhagen, found out about
the hair, which had been excavated from permafrost in the 1980s, from
an associate at the Natural History Museum in Denmark. One of the
difficulties with analyzing ancient DNA is the risk of contamination
from modern human DNA or damage inflicted by bacteria or fungi. But
recent studies have shown that hair tends to protect DNA against the
latter two threats.

Nuka Godfredtsen

An artist's drawing shows a
reconstruction of "Inuk," a Palaeo-Eskimo who lived about 4,000 years
ago on the western coast of Greenland.

Willerslev took special care to guard against contamination as his
group analyzed the sample. Still, these were 4,000-year-old locks, so
it wasn't perfect. "We were dealing with very, very short pieces of
DNA," Willerslev says. "It was a massive puzzle of 3.5 billion pieces
that you have to stick together in the right way."

That puzzle demanded help. Willerslev and his group did the initial
analysis in Copenhagen, then shipped samples to labs in the United
States, China, Great Britain and Australia; other scientists involved
came from Estonia, France and Russia. "It was a huge amount of people
involved in piecing all this together," he says.

The group analyzed more than 350,000 of the genome's single nucleotide
polymorphisms, or SNPs. In modern
people, scientists have been able to link these tiny variations in DNA
to a number of characteristics, so Willerslev and his group scoured DNA
databases for SNPs that Inuk shares with modern people.

The result was an unprecedented level of detail regarding the physical
traits, metabolism and genetic predispositions of this ancient man. "I
was actually quite surprised at the details we could get out of this,"
Willerslev says. "I think it's quite amazing that you could say that
this guy had dry earwax."

Besides ear wax and skin color, the genetic detective work also allowed
the scientists to determine how the Saqqaq relate to other ancient and
modern people. They concluded that Inuk's ancestors migrated to the New
World from Siberia more than 4,400 years ago. Previously, researchers
contended that the Saqqaq people were ancestors of the Inuit and Native
Americans of today, but the genetic analysis shows this is not the
case. "It was very clear that he's not ancestral to modern people found
in the New World," Willerslev notes. "His closest relatives are three
Siberian groups."

Inspired by their success with Inuk, Willerslev and his team are now
turning to a different continent. He plans to use similar techniques on
150 different ancient hair samples collected from all over South
America, some of which date back 8,000 years. This next round of
research will again address migration patterns, he says, but the
scientists will also be exploring a phenomenon that could hold broader
interest. "We're looking into the origin of clothes, and the clothes
culture in the Americas."